Recommendations on screening for syphilis in non-pregnant adults and adolescents

Note: The full statement is being finalized and translated; it will be published as soon as possible. For questions, please contact the NAC-STBBI Secretariat at sti.secretariat-its@phac-aspc.gc.ca.

Preamble

The National Advisory Committee on Sexually Transmitted and Blood-Borne Infections (NAC-STBBI) is an External Advisory Body that provides the Public Health Agency of Canada (PHAC) with ongoing scientific and public health advice and recommendations for the development of sexually transmitted and blood-borne infections (STBBI) guidance, in support of its mandate to prevent and control infectious diseases in Canada.

PHAC acknowledges that the advice and recommendations in this statement are based upon the best available scientific knowledge at the time of writing and is disseminating this document for information purposes to primary care providers and public health professionals. The NAC-STBBI Statement may also assist policy makers or serve as the basis for adaptation by other guideline developers. NAC-STBBI members and liaison members conduct themselves within the context of PHAC’s Policy on Conflict of Interest, including yearly declaration of interests and affiliations.

The recommendations in this statement do not supersede any provincial/territorial legislative, regulatory, policy and practice requirements or professional guidelines that govern the practice of health professionals in their respective jurisdictions, whose recommendations may differ due to local epidemiology or context. The recommendations in this statement may not reflect all the situations that may arise in professional practice and are not intended as a substitute for clinical judgment in consideration of individual circumstances and available resources.

Executive summary

Background

Syphilis is caused by the bacterium Treponema pallidum, and can cause serious health problems if left untreated, and in extreme cases, can result in severe complications like dementia or death. Syphilis progresses through stages with varying symptoms, including primary, secondary, latent, and tertiary stages. The World Health Organization (WHO) estimated 7.1 million new syphilis infections globally in 2020. Infectious (primary, secondary, and early latent stages) and congenital syphilis are also on the rise in Canada; all jurisdictions have declared increased rates of infection. The national rate of infectious syphilis increased from 5.1 per 100,000 population in 2011 to 24.7 per 100,000 in 2020.

Rationale for the guidelines

Sustained and significant increases in Canadian rates of syphilis prompted the National Advisory Committee on Sexually Transmitted and Blood-Borne Infections (NAC-STBBI) to prioritize the review and update of the Public Health Agency of Canada’s (PHAC) existing screening recommendation for non-pregnant adults and adolescents.

Objectives

The objectives of this work are:

• to assess the evidence for syphilis screening in non-pregnant adults and adolescents to inform the development of evidence-based guidance; and
• to update, as required, the existing syphilis screening recommendation.

Methods

A working group composed of NAC-STBBI members was formed at the beginning of the project to undertake this work. These guidelines were developed following the methods outlined in the 2014 WHO handbook^{Footnote 1} for STI experts, clinicians, researchers, and program managers. The research question was “what is the clinical utility of syphilis screening using risk-based approaches versus population-wide approaches for adolescents and adults”? A methodologist and a team of systematic reviewers from the STBBI Guidance for Health Professionals team at the PHAC independently conducted a systematic review, an environmental scan of previously published syphilis screening guidelines and commissioned a rapid review in 2022 by the Canadian Agency for Drugs and Technologies in Health (CADTH)^{Footnote 2}. The evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE)^{Footnote 3Footnote 4} approach and presented to the working group to inform development of the recommendations. Conflicts of interest were managed according to PHAC guidelines, and no conflicts were declared before the recommendations were discussed and finalized. Research implications were also developed by the working group. This Statement has been endorsed by PHAC.

Summary recommendations

This statement provides two screening recommendations for adults and adolescents. Recommendation-1 includes syphilis screening for sexually active adults and adolescents and recommendation 2 includes syphilis screening for high prevalence groups/communities (such as gay, bisexual and other men who have sex with men; people living with HIV; people who are incarcerated; people who access addiction services; certain Indigenous or First Nation communities). Table 1 shows the summarized recommendations.